THIS DAY IN RMR HISTORY: On June 28, 1914, Archduke Franz Ferdinand of Austria, heir presumptive to the Austro-Hungarian throne, and his wife, Sophie, Duchess of Hohenberg, were shot dead in Sarajevo, by Gavrilo Princip, one of a group of six assassins coordinated by Danilo Ilić. The political objective of the assassination was to break off Austria-Hungary’s south-Slav provinces so they could be combined into a Greater Serbia or a Yugoslavia. The assassins’ motives were consistent with the movement that later became known as Young Bosnia. Serbian military officers stood behind the attack.
The assassination led directly to the First World War when Austria-Hungary subsequently issued a 48 hour ultimatum against Serbia, which was partially rejected. Austria-Hungary then declared war on July 28, 1914, marking the outbreak of the First World War.
At this time many in Europe and the British Empire, including Canadians, were feeling that war was a distinct although unwelcome possibility. Canadian Militia units had already started to notice an increase in enlistments.
Partial source: http://en.wikipedia.org/wiki/Assassination_of_Archduke_Franz_Ferdinand_of_Austria